Snubbing device for three-position relays



Aug. 23, 1938.

o, s. FIELD 2,128,205

SNUBBING DEVICE FOR THREE-POSITION RELAYS Filed Feb. 1, 1935 (y s5 s4 2a so 29 4 19 ,J L 20 7T kg 9 FIG. 2. v a7 ZCTL} fi' s fizaa BY MM %4, ATTORNEY Patented Aug. 23, 1938 UNITED STATES PATENT OFFICE Oscar S. Field, Rochester, N. Y., assignor to General Railway Signal Company,

Rochester,

Application February 1, 1935, Serial No. 4,590

10 Claims.

This invention relates to relays, and more particularly to a dampening device for relays of the three-position type.

In certain types of relays, the movable contact operating element, or armature is operated to one extreme position in response to one character of energization of the relay and to another extreme position in response to a diiierent character of energization, but when the relay is deenergized, a biasing means returns the armature from either of these extreme positions to a center position. The contacts closed when the armature assumes one extreme position are usually opened when the armature reaches its center position and different contacts are closed by the other extreme position, but upon de-energization of the relay, it is found that the center biasing means imparts such velocity to the armature during its operation from an extreme to a center position that the momentum carries the armature sufiiciently beyond center to momentarily close the contacts associated with the other extreme operated position. Such momentary closing of these contacts is of course unwarranted by the condition of the relay, and obviously may cause improper control of circuits or apparatus affected by the position of the relay contacts.

In view of the above and other considerations, it is an object of the present invention to provide a dampening means for relay .armature or other devices operable to three positions, so arranged as to prevent an objectional degree of overrunning of the armature in traveling from either extreme position to the center biased position.

Another object of the present invention is to provide such a dampening means which does not in any manner restrict the movement of the armature from a static center position to either extreme position.

Other objects of the present invention include provision of apparatus for obtaining the above objects which is simple and compact in order to obtain the advantages of greater reliability and efiiciency in operation as well as economy in manufacture.

The foregoing objects and others which will be obvious as the description of the present invention progresses are in general accomplished as follows2- The tendency of a three-position device such as an armature to overrun its center position is herein prevented by a dampening means comprising a member carried by the armature in a manner to coact at times with a stationary member when the armature is at or near its center biased position. However, as the action of the dampening means to restrict movement of the armature beyond the center position is not desirable when the armature is at rest in the center position, the dampening device is arranged to be ineffective to restrict the inherently slow movements starting from a center position, but to become efiective to prevent beyond center movements only under dynamic conditions. Specifically, the armature-carried member does not operably coact with the stationary member in a static condition of the armature, but the inertia of a part of the armature-called member when the armature is accelerated toward its center position effects movement of the armature-carried member into a position wherein it does coact with the stationary member to absorb the momentum obtaining in the moving armature upon reaching a center position.

The novel features considered characteristic of the present invention are set forth with particularity in the appended claims. The invention itself however, both as to its organization and its method of operation, together with additional objects and advantages thereof, will best be understood from the following description of a specific embodiment when read in connection with the accompanying drawing, in which:-

Fig. 1 shows diagrammatically an elevational View of the armature'portionof a three-position vane type relay having the present invention applied thereto.

Fig. 2 is a side elevational view of a portion of Fig. 1.

Fig. 3 is a view similar to a portion of Fig.1 1 but illustrating an instantaneous unbalanced condition obtaining during operation of the present device.

The present invention has been shown in the drawing as applied to the movable parts or the armature assembly of a three-position polyphase relay such as used for railway signalling purposes, but it is understood that the present invention is equally applicable to other relays or members of various other devices which are actuated in either of two directions from a biased center position.

In Fig. 1, a horizontal shaft 4 is rotatably carried by suitable anti-friction bearings not shown, which shaft 4 carries an actuating vane 5 fixed thereto and a T-shaped .arm 6 also attached thereto but spaced longitudinally on the shaft 4 according to the arrangement of the other relay parts not shown herein. The means for actuating the vane 5 is immaterial to the present invention, it merely being necessary to understand that the vane 5 is operated either in a clockwise or a counter-clockwise direction from its center position. However this vane may be operated in the same manner as a similar vane of a relay shown in detail in Patent No. 1,882,846 granted October 18, 1932 to W. K. Howe.

The arrangement illustrated for biasing the shaft 4 from either extreme operated position to its center position comprises two weights 1 and 8 attached to outer ends of respective arms 9 and III, which arms operate about a common pivot pin H at their inner ends, the pivot pin H being held by an upwardly extending boss of a stationary member l2 which may be part of the frame structure of the relay. The outer portions of the arms 9 and H] are connected by bearings l5 and IE to respective connecting arms l3 and I4, the upper ends of the arms l3 and I4 being provided with slots I! and I8 receiving pins I9 and 20 respectively which pins are carried at the ends of oppositely extending horizontal arms of the T-shaped member 6.

It will now be obvious that when the shaft 4 is rotated in a clockwise direction, the weight I is raised through the medium of the connecting arm l3, while the weight 8 is not moved, the pin 20 merely moving downwardly in the slot I8, so that the raised position of weight I furnishes the biasing force necessary for returning the shaft 4 back to its illustrated center position. In a very similar manner, the weight 8 is lifted by a counter-clockwise rotation of shaft 4, while the pin l9 moves downwardly in slot [1, to thereby bias the armature towards its center position from its counter-clockwise rotary position.

A movable contact finger 24 is diagrammatical- 1y shown as assuming a center position in accordance with the center position of the vane 5, the contact 24 being carried by an insulating block 25 rotatably mounted in a suitable manner by a center pivot pin 26. A downwardly extending arm 21 is attached to the insulating block 25 and the lower end of arm 21 is connected by bearing 29 to one end of a connecting arm 28, the other end of arm 28 being connected by bearing 30 to the upwardly extending portion of the T-shaped arm 6. With this arrangement, it will be obvious that a clockwise rotation of shaft 4 will rotate the insulating block 25 in a counterclockwise direction thereby moving the movable contact finger 24 downwardly, while a counterclockwise rotation of shaft 4 will result in an upward movement of contact 24 in a similar manner.

The present dampening device is arranged about the extreme upper end of the upwardly extending arm of the T-shaped member 6, and comprises a pivot pin. 34 suitably attached to the extreme upper end of the member 6, which pin 34 carries a pendulum member 35 arranged to rotate freely thereabcut. The lower end of the pendulum member 35 carries a weight 36, while the upper end is enlarged to present a flat horizontal surface, which surface barely clears the lower edge of a stationary member 31 when the member 6 is at rest in the position illustrated in Fig. 1. The member 31 has a wedge-shaped lower end and is suitably fastened to a stationary upright member 38 as shown in Fig. 2, which member 38 may be the frame of the relay. The pendulum member 35 should be mounted on the member 5 at a point considerably above its center of gravity, and for reasons which will later be obvious, the upper horizontal surface should be as close as practical to the pivot support 34. The shaft 4 may obviously be rotated in either direction from its center position shown in Fig. 1 without interference in any manner by the present dampening arrangement as long as the start of such movements is at a reasonable rate of acceleration, the only means holding it in the center position being the weights 1 and 8.

Now considering that the relay is energized in J a manner to operate the shaft 4 in a counterclockwise direction to its extreme left hand posi tion, the pendulum member 35 being free to ro- 'tate about its pivot 34, now moves relative to the member 6 to still hang vertically from its pivot 34. However upon deenergization of the relay, the upper end of member 6 moves in a clockwise direction toward its center position due to the action of the biasing weight 8, and the inertia of the pendulum weight 36 due to the acceleration obtaining during this movement of the member 6 causes the lower end of the pendulum member 35 to lag the movement of its pivot end, thereby operating the pendulum member 35 into an unbalanced position out of its vertical align- 1:

ment,

This displacement of the member 35 from its vertical alignment will be retained until the member 6 reaches its center position and a condition such as shown in Fig. 3 will momentarily exist. In Fig. 3 it is obvious that the lower edge of the stationary member 31 will be engaged by the upper edge of the pendulum member 35 at a point to the left of the pivot 34, and the momentum or kinetic energy obtaining in the moving parts of the relay upon reaching a center position will be absorbed by the impact resulting from the engagement of these two members, thereby stopping the member 6 in its center position.

The member 35 of course returns immediately to a vertical position due to gravity, which return movement is obviously accelerated by its impact on the stationary member 31 so that a beyond-vertical movement may result, but it is contemplated that this will cause an engagement between the stationary member 31 and a point on the upper edge of the pendulum member 35 located to the right of the pivot 34, thereby interfering with rebounding of the member 6.

The action of the present dampening means 4 during a movement of the member 6 from its clockwise rotated position to a center position is very similar to the action just described, or that is, the lower end of the pendulum member 35 will lag the motion of its pivot end, resulting in a displacement of the member 35 out of vertical alignment upon reaching a center position. This displacement of member 35 from vertical is in the opposite direction to that illustrated in Fig. 3, but the resulting impact with the stationary member 31 is effective to stop member 6 in the same general manner.

The dampening means for a three-position rclay armature thus provided is obviously operable to prevent overrunning of the relay armature beyond its center position ordinarily due to the momentum imparted to the moving parts by the biasing means. In the present dampening means, the momentum of the moving parts is obviously absorbed by the impact of the armaturecarried member with the stationary member when the armature reaches its center position, thereby stopping the armature abruptly as the reaction to this impact results in a motion of the armature carried member which acts to prevent a reactive movement of the armature. This prevents the bobbing of the armature so objectionable in ordinary resilient centering means. A very important feature of the present dampening means is its arrangement whereby it does not restrict or in any way add to the effort required to gradually move the armature from a static center position.

The above rather specific description of one form of the present invention is given solely by the way of example, and is not intended, in any manner whatsoever in a limiting sense. It is also to be understood that various modifications, adaptations and alterations may be applied to meet the requirements of practice, without in any manner departing from the spirit or scope of the present invention, except as limited by the appended claims.

Having thus described my invention what I claim is:

1. In a centering means for a three-position relay armature or the like, in combination with a pivoted armature shaft biased to a center position from operated positions either side of the center position, an upwardly extending arm carried by the shaft, a wedge-shaped stationary member positioned above the center position of the arm, a pendulum-like member pivotably carried at the upper end of the arm, and lugs extending horizontally from the pendulum-like member and operable into positions coacting with the stationary member by a response of the pendulum-like member to acceleration of the arm toward its center position.

2. In a centering means for a three-position relay armature and the like, in combination with a pivoted armature shaft biased to a center position from operated positions either side of the center position, an upwardly extending arm on the shaft, a pendulum member pivotably mounted on the arm, a stationary member above the pendulum member, and means on the pendulum member engageable with the stationary member only when the pendulum member is moved out of vertical alignment.

3. In a dampening means for a three-position armature, in combination with a rotatable armature biased to a center position from operated positions either side of the center position, an arm on the armature, a pendulum member rotatably carried by the arm, and a stationary member coacting with the pendulum member only when the pendulum member is not in a state of equilibrium.

4. In a dampening means for a three-position armature, in combination with a rotatable armature biased to a center position from operated positions either side of the center position, an arm on the armature, a pendulum member rotatably carried by the arm, and a stationary member positioned to clear the pendulum member only when the pendulum member is in a state of stable equilibrium.

5. In a, relay having an armature operable in either direction from a biased center position, the combination of an arm on the armature, a pendulum member on the arm, a stationary member positioned in the path of the pendulum member only when the pendulum member is operated out of vertical alignment by acceleration of the armature arm.

6. In a dampening means, in combination, a stationary member, a pendulum member actuable relatively to the stationary member at a pivot support located above its center of gravity, the stationary member coacting with the pendulum member only when the center of gravity of the pendulum member is out of vertical alignment with its pivot support.

7. In an inertia dampening means for vane type relays and the like, in combination, a stationary abutment, a pivoted member freely rockable on its pivot, means for bodily moving the pivoted member and its pivot past the abutment, the pivoted member and the abutment being spaced so that the pivoted member clears the abutment when moved at a uniform rate of speed, the pivoted member being non-symmetrical about its pivot and arranged to contact the abutment when it is sufiiciently accelerated as it is moved past the abutment.

8. In an inertia dampening means for vane type relays and the like, in combination, a stationary abutment, a pivoted member freely rockable on its pivot and having a substantially flat faced part above its pivot, means for bodily moving the pivoted member and its pivot past the abutment in a direction substantially parallel to the flat face, the pivoted member and the abutment being spaced so that the flat faced part clears the abutment when moved at a uniform rate of speed, the pivoted member being nonsymmetrical about its pivot and arranged to contact the faced part and the abutment when the pivoted member is sufliciently accelerated as it is moved past the abutment.

9. In a relay having an armature operable from a biased position, the combination of an arm on the armature, a pendulum member on the arm, a stationary member positioned in the path of the pendulum member only when the pendulum member is operated out of vertical position by acceleration of the armature arm.

10. In dampening means for a relay armature and the like, in combination with a pivoted armature shaft biased to a position from an operated position, an upwardly extending arm carried by the shaft, a wedge-shaped stationary member positioned above the biased position of the arm, a pendulum-like member pivotably carried at the upper end of the arm, and lugs extending horizontally from the pendulum-like member and operable into positions coacting with the stationary member by a response of the pendulumlike member to acceleration of the arm toward its biased position.

OSCAR S. FIELD. 

